Integrating mechanism



J. F. SHANNON E IAL INTEGRATING MECHANISM Oct. 5, 1954 Filed May 2, 1952 2 Sheecs-Sheet 1 FIG.

INVENTORS AND JACK F. SHANNON RANDALL C ABEREGG ATT NEY 1954 J- F. SHANNON ETAL 90,871

INTEGRATING MECHANISM Filed May 2, 1952 2 Sheets-Sheet 2 INVENTORS w 7 AND JACK F. SHANNON Y RANDALL C. ABEREGG Patented Oct. 5, 1954 STA " PTENT OFFECE INTEGRATING MECHANISM Application May 2, 1952, Serial No. 285,736

5 Claims.

This invention relates to improvements in mechanisms for the integration of variables, especially mechanisms for integrating variables with respect to time, and where such variables may be of a physical, chemical, electrical, hydraulic or other nature.

This invention is specifically an improvement of that type of integrator disclosed and claimed in the patent to Gorrie 1,892,183. The Gorrie device was compared in its specification with integrators of the planimeter, or friction contact, type wherein the speed of operation of the register varied in accordance with the value of the variable, while the time of operation of the register was continuous. It was also declared to be known that to obtain a total over any period of time, or integrate a variable with respect to time by periodic determination of the value of the variable, a movement of the register could be made in proportion to the value of the variable. It was suggested the value of the variable be determined at some point of time within the period of interval, and the magnitude of the increments of movement of the register be made of a time length which was a percentage of the time period proportional to the value of the variable.

The Gorrie type of integrator comprises an arrangement wherein predetermined time intervals are chosen and the driving means for the register operated at a constant speed but without the value of the variable at a particular instant during the time interval being the determining factor of the amount of actuation of the register during the time interval. Actually, the Gorrie type of integrator employs a modification of the systems whereinthe length of actuation of the register during each interval of time chosen is in accordance with the value of the variable at a particular instant during that time interval, modified by the value of the variable throughout the actuation. In general, this is accomplished by allowing the value of the variable to change during the time or through that part of the interval of time wherein the register is actuated.

The present applicants now propose a specific arrangement which improves the operation of the Gorrie type of integrators by improving their actuation in provision for a consistent mode of starting the integrating portion of their cycle.

The Gorrie type of integrator may be generically referred to as an escapement type of integrator and the present invention gives, as a specific object, an improvement to the means by" which the escapement wheel of these integrators is arrested and released during its nonintegrating and integrating periods.

In the drawing:

Fig. l is an isometric and diagrammatic repre sentation of our invention in connection with an escapement type of integrator responsive to a variable.

Figs. 2-7 are diagrammatic representations of positions and movements of structure at illustrative portions of the cycle of operation of our invention.

It is often desirable to integrate quantitative variables with respect to time to determine the total, or cumulative, quantity of the variable passing a given point during a specific interval of time. As a device responsive to a variable, we specifically disclose a Bourdon tube l receiving a fluid pressure through conduit 2. This arrangement is based on the premise that a fluid pressure will be determined, by a transmitting mechanism not shown, which will have a value proportional to the variable to be integrated. Obviously the Bou'rdon tube may be replaced by a bellows or a mechanical link may be positioned in space in accordance with the value of the variable.

Regardless of the type of responsive mechanism employed, or the arangement of linkage necessary to be positioned in accordance with the variable, the ultimate objective is the rotative positioning of shaft 3 in accordance with the variable. A pointer 4 is rigidly attached to shaft 3 to move therewith and cooperate with the scale 5 for giving visual representation of the variable. Oi course a chart moving with time may be substituted for scale 5 and a recordin pen may be substituted for pointer d to cooperate with the chart and give a permanent and continuous record with respect to time. I

We have arbitrarily chosen to show the mechanism as it positions at a time in its cycle when the variable is at The time in its cycle is when no integration is taking place and the particular structure of our invention is in position, performing one of its functions. It is obvious that, as the variable positions over this range of values, link 6, attached to shaft 3, positions a point 1 between the maximum and minimum limits marked off by lines A and B.

We provide in connection with the mechanism a register 8, having graduated dials moving in connection therewith, for affording a continuously available means of reading the accumulated total of the variable for any desired time interval by subtracting the reading of the dials of the register 8 at the beginning of the interval representing the total of the variable between the beginning and the end of the interval of time.

Register 8 is driven by means of register shaft 9 which is in turn driven through gears Hi by escapement w eel l4. Escapement wheel i is turned by motor [2 through friction clutch !3 when not retarded by pawls engaging the teeth at its periphery. It is this escapement wheel i4 which is released by the pawls at a predetermined time to rotate for increments of time proportional to the vaiue of the variable. The shaft upon which escapement wheel 14 is mounted is here shown as hollow to allow the shaft I i to protrude therethrough for the support of cam 33. Shaft H, going back through the hollow shaft upon which escapement wheel 14 is mounted, is connected to that shaft of motor I2 upon which is mounted cam 28.

To provide a means for locking and unlocking escapement wheel i4, connected to register 8, there is provided pawls 29 and 39.; which cooperate to sequentially engage the wheel so it will rotate for periods of time proportional to the value of the variable to be integrated.

All of the structure described thus far, with the exception of pawl 30, finds its direct analogy in the disclosure of the Gorrie patent with the arrangement such that actuation of register 8 will be allowed, the escapement wheel being unlocked, mechanically moving out of engagv merit therewith, the pawl 30. When the pawl is moved out of engagement with escapement wheel Hi the friction means l3 causes the wheel and register to be driven at a constant rate of speed by motor [2. In distinction from the (Ziorri device, we desirably unlock the escapement wheel periodically for a time portion of each cycle, of a length determined by the value of the variable at the end of the period. As the single pawl of the Gorrie device begins and ends the integrating period, modification of the period can take place during the period and the modification taken into the integration completely. With the present arrangement of the integration beginning at a precise point of the cycle the value of the variable at the end of the integration determines the period with reference to the fixed point of initiation.

We come now to a consideration of the function of pawl 29 as carried by pivoted member 2! which takes the pawl into and out of engagement with the teeth of wheel M. Member 2| pivots about pivot shaft 22 which is given a substantially vertical adjustment for purposes of calibration by the pivoted support at 23. That part of member 25 extending past the pivoted shaft 22, on the side opposite from pawl 25, is formed into a counterweight and extension member 24 which serves to normally maintain member 2! pivoted counterclockwise but which offers a horizontal under-surface upon which pin 25 lifts to rotate the member 2| counterclockwise.

Pin 25 is carried by beam 26 between point 'i and roller 21. With point 1 positionable, in accordance with the variable, between space limits A and B, and with roller 21 continuously recip rocated at a substantially uniform speed between space limits C and D by rotation of the cam 28 as driven by the motor E2, the pin 25 traverses a predetermined path in a single plane in space. An adjustment 29 is provided for pin 25 on lever 28 to give a positional adjustment for the pin along the longitudinal axis of the beam 26.

The speed of the cam 28 might be in the nature of one revolution in ten seconds, and the actuation of the register 3 at intermediate or other speeds as determined by the internal gear reduction of the regi ter and the ratio gears it). This proportion between the cycles of actuation predetermines the frequency with which the variable is scanned by the mechanism. It can also be generalized "that the member 23 arranged for positioning along a definite path, within limits of travel, in a single plane and in such manner that movement of the member is angularly about either end by the positioning of the opposite end between definite limits of travel, to the er that the actuating pin 25 assumes a position x; ween limits of travel in dependence upon the position of pivot 7 between A and B and the roller 2? between C and D.

Thus, at any given value of the variable corresponding to the definite postion of the pivot 1 between A and B, the actuating pin 25 is reciprocated alon a definite path in the plane of movement of the member 26 and by the reciprocation between the limits C and D for the roller 21. When the value of the variable is zero and the pivot i is at location B, then the reciprocation of the pin 25 is to be adjusted so as not to cause engagement with extension 2-3 of member 2|. However, when the pivot 7 is at point A, then the pin 25 will be adjusted to bear against the extension 24 of member 2! throughout the entire or major portion of the reciprocation between. the limits C and D for roller 21.

It is obvious from the teachings of Gorrie that when actuating pin 25 engages the extension 25, the pawl 25 is d engaged from es apement wheel l4 and the friction it allows the motor !2 to drive the register The length of time through which the locking wheel is allowed to rotate and register 8 driven, is determined by that portion of time cycle of cam 28 through which the actuating pin 25 engages the extension 2 and such portion is determined by the position of pivot 1 along the vertical path between limits A and B.

Now as the cam 23 is rotated counterclockwise, the position given pivot, or point, '5 along th path between limits A and 35 determines the portion of its cycle during which the register 8 is driven. If the variable changes in value during the period of integration, the position of pivot "s will shift and the amount of time the integrator driven willbe correspondingly modified. In general it may be stated that the registe movement during each cycle of cam 28 is a function of value of the variable and its change throughout that cycle.

A certain definite relationship desirably exists between the location of the actuating pin 25. pivot and the point of contact between 25 and 24 as well as between the roller 23' and cam 23. This relationship and its eifect upon the actuation of the mechanism is elaborately disclosed in the Gorrie patent. In order to make the relative adjustments, the adjustment structure at 23 and 29 has been provided for moving the pin 25 and member 24 into desired positions. An exhaustive analysis of the effect of these adjustments is set forth in the Gorrie patent and forms no part of the present invention.

The present invention is concerned with im proving the manner in which escapement wheel I4 is arrested and released. Hereinafter referring to pawl 20 as the main pawl, it may be seen in Fig. 1 that we have provided a second pawl structure 30 which is carried by member 31, pivoted at 32 when actuated by cam '33 against the action of spring 3 5. Specifically, the present invention finds its embodiment in the cooperatingstructure which causes pawl 33 to periodically relieve the engaging stress between the main pawl 20 and the escapeinent Wheel I i prior to disengagement of pawl 23 from the teeth of escapement wheel It.

It has long been evident, to some extent at least, that in the functioning of the Gorrie type of integrator, the withdrawal of main pawl 20 from its tooth, the linkage, including the indicating and/or recording mechanism, has been given enough reaction to disturb the recordation. When the comparatively slow moving chart cooperates with a pen which is regularly vibrated, or jarred, the record is a wide band bridging over and obscuring the true record. This reaction given the linkage could well be due to the bending stress set up in the member 2! as a beam subjected to a flexure force from engagement with the escapement wheel tooth; the sudden removal of the force could cause the member 21 to snap back into its normal shape and react through the linkage. However, when the present invention is correctly adjusted, pawl '30 is manipulated to engage a tooth of escapement wheel M in order to reverse the direction of rotation of wheel M for a predetermined increment in order that when the main pawl 20 is pushed clear of the periphery of wheel it by pin 25 there Will be no disturbance imparted to the linkage.

The cooperation of cam 33, member 3! and spring 3 5 can be readily discerned from an examination of Fig. 1. Cam 33 is arranged to have substantially 180 of fixed high dwell for the follower portion of member 3| and substantially 180 of low dwell. With cams 33 and 28 both mounted on shaft H, it can be appreciated that these high and low dwell periods of cam 33 are timed with reciprocating cam 28 in order that the escapement wheel I l is released by the relief pawl 30 to start the period of integration in which register 8 is actuated, with subsequent stopping of the escapement wheel by the main pawl after an interval proportional to the magnitude of the variable. The more pertinent steps in this cooperation are delineated in minute detail in Figs. 2-7.

Fig. 2 illustrates the relative positions of the novel structure at the time when escapement wheel it is prevented from rotating by the main pawl. The follower of 3| is shown on the high dwell portion of cam 33 and the relief pawl 30 is swung away from engagement with the escapement wheel teeth by the adjustable eccentric 35 on member 3 I.

Fig. 3 depicts the relative position of the structural components when both cams 33, 28 have rotated counterclockwise until the follower of member 3i has completed one-third of its descent toward the low dwell. The arrangement is such that the tip of pawl 30 touches the tooth tip circle at one-third of the drop. Here again, the adjustment 35 is available to insure this relation.

Fig. 4 illustrates how when two-thirds of the drop of cam 33 has been completed the relief pawl tip has completed its entry into the tooth along an arc tangential to th bisector of the tooth angle at its root.

Fig. 5 illustrates the action when the cam follower of 3i has taken the complete drop of cam 33. Relief pawl 33, under the urging of spring 34, has rotated escapement wheel l4 clockwise approximately half the span between adjacent tooth tips.

Fig. 6 illustrates how the main pawl 21! now swings clear of its tooth without any disturbance of 'its connected linkage at some point along cam 28 dictated by the variable position of pin 25 controlled by cam :28. It is clearly illustrated how this extraction of the main .pawl occurs during the low dwell cooperation between the follower 3! and the cam 33.

Fig. 7 shows the cooperation of the novel elements in the rise from the low to the high dwell on cam 33. In this rise, which is timed to occur at the highest point of rise for roller 27, the toothed wheel it is released to begin the integrating period of actuating register 3. Therefore, the integrating period may be designated as lying between this high dwell of cam 23 and some point prior to its low dwell. It can readily be appreciated that with this arrangement of our novel structure the integrating period extends over only one-half of cam 28 at of the variable. Therefore, to pass the same number of teeth of the escapemcnt wheel for an integrating period motor i2 will have to be operated twice as fast as in the prior arrangement of the Gorrie device.

It is apparent that our invention can be adopted to other types of integrators. Fundamentally the stress relieving disturbances are shifted to a portion of the mechanisrnfrom which no reaction will be imparted to the record. Also, as the beginning of each cycle is made more precise, over-all accuracy is improved. The Gorrie integrato-r could be set up with exact linkage position and yet have its main pawl creep up the sides of engaged teeth of the integrator wheel until whole teeth were shipped. Part of this tendency was often due to imperfect fashioning of some of the teeth. However, vibration has promoted some skipping of teeth by starting the creep up a tooth side. In any event, the operation of the present invention in having the integrating period begin precisely with the main pawl in the middle of a tooth span, cumulative errors from imperfect teeth, or from vibration, are practically eliminated.

What we claim as new, and desire to secure by Letters Patent of the United States, is:

1. In an integrator; a register operated by a shaft which is normally looked, a driving shaft operating at a constant speed, friction means connecting the shafts, two cams mounted on the driving shaft, a member adapted to be positioned from one end by the first of the cams along a definite path in a plane at a substantially uniform rate between limits of travel and from the other end in the plane in accordance with a variable, a first pivoted pawl member for locking the register shaft, actuating structure on the positioned member for pivoting the first .pawl out of locking relation with the register shaft, and a second pivoted pawl for retaining the register shaft in the locked position given it by the first pivoted pawl and being subsequently actuated by the second cam to release the shaft after release by the first pawl.

2. In the integrator of claim 1 where the first of the cams is a linear rise cam which reciprocates one end of the positioned member along a definite path within limits of travel while the other end is positioned in the plane within definite limits of travel and proportional to the value of the variable to be integrated with respect to time.

3. In the integrator of claim 2 where the second cam has two uniform spans of dwell over substantially of rotation which control the second pivoted pawl to alternately lock and release the register shaft.

i. In the integrator of claim 3 where the descent of the follower of the second pivoted pawl from high to low dwell on the second cam causes the pawl to reverse the rotation of the register shaft a predetermined amount.

5. In an integrator; a register operated by a shaft which is normally looked, a driving shaft operating at a constant speed, a shaft bearing a toothed escapement wheel and operatively connected to the register shaft, friction means connecting the escapement wheel shaft and the driving shaft, two cams mounted on the driving shaft, a beam member adapted to be positioned from one end by one of the cams which reciprocates the end along a definite path in a plane at substantially uniform rate between limits of travel and the other end is positioned within limits of travel in the plane in accordance with the value of the variable to be integrated, a first pivoted pawl mechanically urged into position for engaging the teeth of the escapement wheel to prevent its rotation, an actuating structure on the positioned beam member for pivoting the first pawl from out of engagement with the escapenient wheel teeth, and a second pivoted pawl actuated by the second of the cams to engage the teeth of the escapement wheel after it is locked by the first pawl against integrating rotation and reversing the direction of rotation of the toothed wheel a predetermined increment of angular movement prior to withdrawal of the first pawl from engagement with the teeth.

6. In an integrator having an escapement type of movement wherein; a register is operated by a driven integrating shaft, a driving shaft normally operated at a constant speed, a friction means connecting the shafts, a first locking means differentially operable for controlling the integrating shaft, and a first releasing means actuated from the driving shaft for actuating the first locking means; the improvement including, a second locking means uniformly operated for controlling the integrating shaft, means for normally positioning the second locking means into locking position with respect to the integrating shaft while the first locking means is in looking position, and a second releasing means actuated from the common driving shaft for actuating the second locking means subsequent to actuation of the first locking means by the first releasing means from the driving shaft.

1. In an integrator having; a register operated by a shaft which is normally looked, a driving shaft operating at a constant speed, friction means connecting the shafts, a first means for locking the shaft of the register for variable intervals, a first release cam means rotated from the driving shaft to actuate the first means; the improvement including, a, second means for looking the register shaft for uniform intervals, means for moving the second means into engagement with the register shaft as the first means References Cited in the file of this patent UNITED STATES PATENTS Name Date Gorrie Dec. 2'7, 1932 Woolley Apr. 3, 1934 Number 

